To meet the demand for wireless data traffic, which has increased since deployment of 4th-generation (4G) communication systems, efforts have been made to develop an improved 5th-generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘beyond 4G network’ or a ‘post long-term evolution (LTE) system’.
It is considered that the 5G communication system will be implemented in millimeter wave (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To reduce propagation loss of radio waves and increase a transmission distance, a beam forming technique, a massive multiple-input multiple-output (MIMO) technique, a full dimensional MIMO (FD-MIMO) technique, an array antenna technique, an analog beam forming technique, and a large scale antenna technique are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, a D2D communication, a wireless backhaul, a moving network, a cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, and the like.
In the 5G system, a hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and a sliding window superposition coding (SWSC) as an advanced coding modulation (ACM) scheme, and a filter bank multi carrier (FBMC) scheme, a non-orthogonal multiple Access (NOMA) scheme, and a sparse code multiple access (SCMA) scheme as an advanced access technology have been developed.
Generally, in a D2D communication system, a device identifies neighbor devices which are proximate to the device itself, and transmits and receives data by establishing a radio link with a specific neighbor device if necessary. This process for establishing a radio link and transmitting and receiving data is locally performed among devices without assistance of additional apparatus, so a D2D communication system has an advantage that rapid market introduction is possible without additional infrastructure compared to other wireless communication system. Further, a D2D communication system may solve a traffic overload problem which is concentrated on a base station or an access point (AP) by locally accepting data traffic.
So, a standard organization such as a 3rd generation partnership project (3GPP), and a institute of electrical and electronics engineers (IEEE) has standardized a D2D communication standard based on long-term evolution advanced (LTE-A), wireless-fidelity (Wi-Fi), and/or the like, and various D2D communication schemes have been developed. Recently, a 3GPP has actively progressed a standardization study for supporting a proximity service among devices. Specially, a D2D communication scheme which may increase a data rate between neighbor devices and may decrease transmission delay between the neighbor devices has been considered as a scheme which is appropriated for supporting the proximity service among the devices.
Meanwhile, a 3GPP uses a relay node (RN) in order to increase network capacity of a long term evolution (LTE) system and extend a service coverage.
A structure of a general LTE mobile communication system including an RN will be described with reference to FIG. 1.
FIG. 1 schematically illustrates a structure of a general LTE mobile communication system including an RN.
Referring to FIG. 1, the LTE mobile communication system includes an evolved packet core (EPC) 110 and an enhanced-universal terrestrial radio access network (E-UTRAN) 120. The EPC 110 includes an mobile management entity (MME)/serving-gateway (S-GW) 111, and an MME/S-GW 113, and the E-UTRAN 120 includes an enhanced node B (eNB) 115, a donor eNB (DeNB) 117, and an RN 119.
The RN 119 relays a control signal and data traffic between the LTE mobile communication system and a user equipment (UE) by connecting a backhaul link with the LTE mobile communication system using a Un interface as a radio interface.
The DeNB 117 is an eNB which supports relay communication of the RN 119, supports a network access of the RN 119, and modifies a communication parameter of the RN 119 by periodically or a periodically transmitting a control signal.
The EPC 110 performs an authenticating operation for the RN 119, and performs an operation for providing parameters used for communication of the RN 119, and the like.
In an LTE mobile system, an RN is deployed within a service coverage of a cell or at a boundary of a service coverage of a cell, and supports communication for a UE which exists at a hot-spot area, a shadow area, and a cell boundary area. However, an RN is generally deployed at a fixed location, so the RN is difficult to support communication for a shadow area which may fluidly occur.
Further, an RN is additionally deployed and operated by a service provider, so deployment and operating cost is relatively expensive. Specially, if an eNB or an RN at a specific area does not perform a normal function due to occurrence of a disaster, UEs which exist at the specific area may not perform normal communication.
So, in an LTE mobile communication system, there is a need for a scheme for providing normal communication for UEs which exist at a disaster area, a shadow area, a cell boundary area, and the like.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.